In the past, there have been refrigeration apparatuses for performing a vapor-compression refrigeration cycle, the refrigeration apparatuses performing a defrosting operation for eliminating frost adhering to an evaporator in circumstances such as winter or cold regions. For example, in the refrigeration apparatus disclosed in Japanese Laid-open Patent Application No. 2014-105891, when frost has formed on a second heat exchanger (an evaporator) during a heating operation for heating water by heat exchange between refrigerant and water in a first heat exchanger (a radiator), a defrosting operation is performed in which high-pressure gas refrigerant (hot gas) is sent to the second heat exchanger by switching the state of a four-way switching valve, and the frost is eliminated.
In Japanese Laid-open Patent Application No. 2014-105891, to shorten the time associated with the defrosting operation, before the defrosting operation is begun a heat storage operation is performed in which refrigerant enthalpy in the intake side of a compressor is increased while pressure loss in a refrigerant circuit is reduced by channeling refrigerant from a point midway through a refrigerant passage joining the first heat exchanger and the second heat exchanger, to a bypass passage allowing refrigerant to bypass to the intake side of the compressor, thereby increasing the amount of heat stored in the high-pressure side of the refrigeration cycle.